I'm trying t swap in a new vacuum canister on my Pertronix Flamethrower Distributor and can't figure out how to remove the round black disk just above the can.

There is a white plastic section just below where the springs/weights mount and looks like a snap ring under that. :confused:

Anyone else swapped canisters on one of these?

Tom

Can't tell by the angle of the picture but do any of the holes line up with the can screws if you rotate the disk? If not you may have to drive out the roll pin in the drive gear and pull the shaft out the top.

drove the roll pin out, pulled the shaft, got the new B-20 can in and now I can't get the shaft to seat properly. Its short by about 1/2 the diameter of the roll pin. Any tricks I am missing?

thanks
Tom

got it, didn't have the weights seated all the way.
If you are swapping the canister on a Pertronix billet distributor, you need to pull it, remove the drive gear, pull up the shaft, remove a snap ring holding the disk that advances the timing from the canisiter... :clonk:

I have been doing this exact thing except I was trying to install an adjustable canister. That is the one thing I HATE about the Pertronix unit. The hei's you can just pull the can without pulling the dizzy. I think I may go to a DUI HEI unit with their Mini VIP 18volt booster. Did your dizzy come with a b22 canister? Mine did. It advances 16* at 16"-18" of vacuum. What vacuum does your engine make? Also, is your car an auto or manual? I ask because they say you need a can that is all in at your idle vacuum, but if it's an auto, you need to be in gear. The vacuum drops by about 2"-3" once in gear. You also need a canister that is fully advanced at 2" of vacuum BELOW what your engine produces. If you vacuum can is not fully advanced at idle, you get an unstable idle.

Did your dizzy come with a b22 canister? Mine did. It advances 16* at 16"-18" of vacuum. What vacuum does your engine make? Also, is your car an auto or manual?

Charlie- the Pertronix came with a B22 canister. My idle is at 850-900rpm with 9-10" vacuum. The can is hooked up to ported vacuum right now - good stable idle with initial timing at 12 deg - no overheating problems - 5 speed TKO-500

At cruise I get about 14-15" vacuum so the B20 should pull in about 16 deg at 11-13" vacuum

One other interesting thing - when I ordered the B-20 canister from NAPA, I ordered two: VC1765 for $12.99 and VC 1765SB for $7.69. I wanted to see what the difference was. Its the same canister and they are both stamped B26.

According to Lars spec sheet the B20 and B26 are rated the same.
http://www.corvette-restoration.com/resources/technical_papers/Vac_Adv_Spec.pdf

Charlie- the Pertronix came with a B22 canister. My idle is at 850-900rpm with 9-10" vacuum. The can is hooked up to ported vacuum right now - good stable idle with initial timing at 12 deg - no overheating problems - 5 speed TKO-500

At cruise I get about 14-15" vacuum so the B20 should pull in about 16 deg at 11-13" vacuum

One other interesting thing - when I ordered the B-20 canister from NAPA, I ordered two: VC1765 for $12.99 and VC 1765SB for $7.69. I wanted to see what the difference was. Its the same canister and they are both stamped B26.

According to Lars spec sheet the B20 and B26 are rated the same.
http://www.corvette-restoration.com/resources/technical_papers/Vac_Adv_Spec.pdf


Whatever can you use MUST be all in at idle. I have the same file from Lars. It is very informative. It definately says that the can must be fully advanced at idle. It also says that whatever can you use, it needs to be fully advanced 2" of vacuum BELOW what your engine makes. You make 9"-10" at idle so you need a can that is fully advanced at 7". You are fine at cruise, but at idle the canister needs 11"-13" of vacuum. I would try advancing the initial to around 16*-18*. That will give you more vacuum. You will probably be better off with an adjustable canister.

You will probably be better off with an adjustable canister.

I agree, if this canister doesn't work out I will probably go with an adjustable. I'm going to experiment with the initial and total timing this weekend.

You engine does not make sufficient vacuum to pull the B20 to its fully advanced position at idle. You are in the same situation I was in before I went to the TKO. You will need an adjustable canister.

I'm going to give the B-28 canister a try before the adjustable can.
After re-reading Lars and JohnZ explanations, that canister should work out. Besides... I am getting good at taking it apart and putting it back together:D

Watch the adjustable units. I had the Crane one in my MSD 8361 and like 67CamaroRS/SS metioned I needed a can that was all in by at least 7". Idle vacuum was 9" with my manual trans. Anyway, the Crane unit would only start to pull in at around 5" no matter which direction I had the allen key turned. Lowest all in I was able to achieve was at 10.5-11". I gave up on it and put a B28 can in. Limited to 10 degrees it starts pulling in at 4.5-5" and is all in by 7-7.5". Car idles and runs excellent now. Be warned you cannot get a B28 unit from NAPA any longer. I got mine at Autozone under #DV1810. I originally ordered 2 thru GMPartsDirect (88924985) but was told they were on back order so I tried the AZ unit. Got that one in next day and when I got back to the house the 2 from GM were there also!! I want one as a spare, but I also now have an extra!!:clonk:

Be warned you cannot get a B28 unit from NAPA any longer. I got mine at Autozone under #DV1810.

you are correct! NAPA online says to go your local retailer and the local guys can't get it. Strange since its obvioulsy still available from others.

I ordered the AC-Delco PN from Rockauto; the NAPA VC-1810 canister is also known as GM PN88924985 and AC-Delco #D1312C (aka "B28")

you are correct! NAPA online says to go your local retailer and the local guys can't get it. Strange since its obvioulsy still available from others.

I ordered the AC-Delco PN from Rockauto; the NAPA VC-1810 canister is also known as GM PN88924985 and AC-Delco #D1312C (aka "B28")

Available from GM Parts Direct also. After conversing with John Z he infomed me to switch to the 1810 and the improvement was perfect. For those who have not read Lars' and John's articles it is high on the must read list. They concur on most data.

B-28 canister is in and all canister timing is now in at idle!
Also switched canister to full manifold vaccum. No need for an adjustable canister at this point.

Since I never did find any detailed views on taking apart a Pertronix Billet distributor - am posting some pics - hopefully this makes someone else's canister install go smoother. Its now about a 30 minute job from removing the distributor to setting the timing:beers:

On a side note, how old is your dizzy? I ask because I am thinking about swapping the Ignitor II for the new Ignitor III. They said it has a built in rev limiter and it produces a multiple spark throughout the entire RPM range, just like their Second Strike Ignition box.

I have the D100700 - bought it new in spring of 2006. The new ignitor III sounds good!

Tom